HARTFORD — Animal rights activists today will ask lawmakers to take the monk parakeets of southwestern Connecticut off a list of invasive species.

The activists hope to prevent the United Illuminating Co. from killing the birds.

After 35 years of tenacious survival, the large green birds, which live in huge communal nests made from twigs, have become an important part of the coastal ecology, parakeet proponents will claim at a public hearing before the General Assembly's Environment Committee. Rep. Richard Roy, D-Milford, the co-chairman of the committee, whose district includes dozens of monk parakeet nests and possibly hundreds of bird lovers, said Thursday that he hopes to protect them from the type of eradication by UI that killed nearly 180 birds last year.

"It's all part of an invasive species bill," Roy said of the legislation, which must be approved by the committee's Monday afternoon deadline to survive. He said the new law must be written carefully if it is to protect the birds.

"What we're trying to do is take them off the invasive species list in a way that doesn't take all species off the list," Roy said. Roy said the bill is just aimed at keeping the parakeets from being annihilated.

In a related development, UI filed a motion to dismiss a lawsuit that seeks a permanent injunction barring the utility, which received help from the U.S. Department of Agriculture, from capturing and killing the birds.

Last year's program targeted more than 100 nests on UI utility poles in West Haven, Milford, Stratford and Bridgeport. Some of the nests had grown over a number of years to several hundred pounds housing several generations of birds.

Since the end of the eradication effort last December, the parrots not killed by the USDA have returned and begun reconstructing 15 to 20 of their nests, said Albert Carbone, UI's spokesman.

Roy said it's up to UI to tear down new nests as they develop, with the hope that the birds will eventually nest somewhere else, possibly on alternative nesting platforms that are being erected in Fairfield and West Haven.

"If they take down the nests several times in a row, maybe the birds will move on and find something else," Roy said.

Although most of the birds — which are actually parrots, despite their name — build their nests in large trees, many birds found the utility poles to their liking. Priscilla Feral, president of the Darien-based Friends of Animals Inc., which filed the suit against UI, said that changing the law is crucial to the bird's survival. She said they believe there is no federal law that classifies them as invasive.

"There is interest in the community to provide protections for them and to let the birds go about the business of living," Feral said. "We're also not aware of any evidence or proof they've caused fires or are a public safety hazard and they've never caused agricultural problems."

FOA attorney Derek V. Otis of Manchester, in a phone interview, described UI's legal motions as avoiding the real questions.

"They said that one of the reasons to dismiss the case was that they're not killing the birds right now, which is clearly ridiculous," Otis said, stressing that without a court order they could resume the killing process at will.

"We have no plans to capture monk parakeets," Carbone said, adding that the issue isn't subject to litigation, because UI is no longer capturing birds.

Last year, FOA filed a similar suit, but UI suspended the program, in which UI crews captured birds at night and handed them to USDA crews, which placed them in carbon dioxide chambers as part of the utility's $125,000 eradication effort.